Abstract:

In this work, we have studied the interaction between graphene oxide (GO) and the biomolecules immobilized
on an electrode surface, which has been further employed to develop new kind of biosensors by fabricating gammaglutamyltransferase
(γ-GGT) sensor as an example. Specifically, glutathione (GSH) is firstly immobilized on the surface
of a gold electrode, and GO nanosheet is introduced to recognize the charge change of GSH caused by the catalysis of
γ-GGT. Then, the introduction of reductant and Ag+ induces silver deposition and partial reduction of GO, forming GOAgNPs
complex for electrochemical readout. Since this complex may have excellent electric conductivity and the solidstate
voltammetry of Ag/AgCl can provide a well-defined symmetrically sharp silver stripping peak, a sensitive electrochemical
biosensor for the detection of γ-GGT is thus developed. Moreover, the experimental results obtained in this work
indicate that GO itself can serve as a general recognition element for biosensor fabrication and GO-AgNPs can be a promising
material in a general sensing platform, so such kind of more biosensors can be developed in the future.

Abstract:In this work, we have studied the interaction between graphene oxide (GO) and the biomolecules immobilized
on an electrode surface, which has been further employed to develop new kind of biosensors by fabricating gammaglutamyltransferase
(γ-GGT) sensor as an example. Specifically, glutathione (GSH) is firstly immobilized on the surface
of a gold electrode, and GO nanosheet is introduced to recognize the charge change of GSH caused by the catalysis of
γ-GGT. Then, the introduction of reductant and Ag+ induces silver deposition and partial reduction of GO, forming GOAgNPs
complex for electrochemical readout. Since this complex may have excellent electric conductivity and the solidstate
voltammetry of Ag/AgCl can provide a well-defined symmetrically sharp silver stripping peak, a sensitive electrochemical
biosensor for the detection of γ-GGT is thus developed. Moreover, the experimental results obtained in this work
indicate that GO itself can serve as a general recognition element for biosensor fabrication and GO-AgNPs can be a promising
material in a general sensing platform, so such kind of more biosensors can be developed in the future.